Electrically actuated remotecontrol apparatus



April 1949. A. R. E. ARNOT 2,467,454

ELEGTRICALLY ACTUATED REMOTE-CONTROL APPARATUS Filed April 25, 1945 2Sheefs-Shet 1 April 19, 1949. ARNQT ELECTRICALLY ACTUATED REMOTE-CONTROLAPPARATUS Filed April 25, 1946 2 Sheets-Sheet 2 Patented Apr. 19, 1949ELECTRICALLY ACTUATED REMOTE- CONTROL. APPARATUS Alfred Reginald ErwinArnot, London, England, assignor to Rotax Limited, London, EnglandApplication April 25, 1946, Serial No. 664,777 In Great Britain March 5,1945 Section 1, Public Law 690, August 8, 1946 Patent expires March 5,1965 3 Claims.

This invention has for its object to provide improved electricallyactuated remote-control apparatus of the kind in which a reversibleelectric motor is controlled by a pair of potentiometers, one of whichis manually operable and is situated at a distant position, and theother of which is operable by the motor.

In the accompanying sheets of explanatory diagrams:

Figure 1 illustrates one form of electrically actuated remote controlapparatus in accordance with the invention.

Figure 2 illustrates a modified form of the invention,

Figures 3 to 8 illustrate modified details.

In carrying the invention into effect as illustrated in Figure 1, Iemploy a reversible electric motor a which is required to impart to amechanism movements in response to signals received from a distantstation, and I arrange in association with this motor a pair ofelectro-magnetic contactors 0. Each of these contactors comprises amagnet winding d, an armature e carrying three contacts f, f f threecomplementary fixed contacts g, g g and a resistance :1 in series withthe winding, the arrangement of the contacts being such that an initialmovement of the armature closes the contacts g and opens the contacts f9 for bringing the motor a into action, and further movement of thearmature also closes the other contacts f g for putting out of actionmeans whereby the rate of motion of the motor is retarded. Such meansmay consist of a normally-operative brake adapted to be released by anelectro-magnet, the winding of the latter being indicated by k.Alternatively the motorretarding means may consist of a resistance whichcan be interposed in any suitable part of the motor circuit. One of thecontactors serves to set the motor a in motion in one direction, and theother to set the motor in motion in the opposite direction. To enablethis to be effected the motor a, may be series wound and provided with apair of oppositely wound field windings m, in which case one of thecontactors 0 controls the circuit through one of the field windings, andthe other controls the circuit through the other field winding.

In association with the two contactors c are arranged a pair ofnormally-open electro-magnetic relays n of the polarized or moving-coiltype. Each of these relays comprises a fixed contact o situated betweena pair of movable contacts p, and an armature (not shown) for actuatingthe movable contacts, the direction of motion of the armature beingdependent on the direction of current through a winding q forming partof the relay. One of the relays n (which is herein termed the firstrelay) serves to control the supply of current directly to the winding(1 of either of the two contactors c, and not through the associatedseries resistance :1 above mentioned. Thus, when the armature of thefirst relay n is moved in one direction from its normal position itcauses the circuit of one of the contactor windings d to be closedindependently of the corresponding resistance a, and when moved in theopposite direction it causes the circuit of the other contactor winding,to be closed in a similar manner. The other of the relays n (which isherein termed the second relay) controls the supply of current to one orthe other or the contactor windings d through the corresponding seriesresistance y. In this case, the contactor 0 brought into action by thesecond relay n closes only the corresponding contacts J, g and leavesthe above mentioned motor-retarding means in action. Preferably and asshown the second relay n is provided with another winding 1 which whenenergised assists the corresponding winding q.

Current is supplied to the relays n, contactors c and motor a from acommon supply system 3 under the control of a pair of potentiometers tof any convenient and appropriate form, one of the potentiometers beingoperable in response to movement of the motor a, and the other beingresponsive to manual operation and situated at a distant position.

In the example illustrated by Figure 1 each potentiometer 22 comprisesan annular main resistance it having its ends connected to the supplysystem 3, and having a contact '0 which is movable around the mainresistance by a spindle w, the contact being connected to the circuitcontaining the winding q of the first relay n. Also the ends of the mainresistance u are connected to the ends of a relatively short subsidiaryresistance a: of segmental form, and the spindle w which carries thecontact 1) also carries two sets of equi-spaced and alternately arrangedcontacts y, ,2 which can be moved over the subsidiary resistance. Itwill be understood that the contacts 22, y, a are secured to and movablesimultaneously by the spindle w. The two sets of contacts y, a arerespectively connected to a pair of slip rings v2, 3 on the spindle w,and the arrangement in such that not less than one of these contacts andnot more than two can be in contact with the subsidiary resistance u atany time, The slip ring 2 is connected to the circuit con-- taming oneof the windings q of the second relay n, and the other slip ring 3 isconnected to the circuit containing the other winding r of that relay,the arrangement being such that when both windings are energised theyassist each other. A potentiometer as above described forms the subjectmatter of my co-pending application Serial No. 664,776, now Patent No.2,442,228, patented May 25, 1948.

The arrangement of the potentiometers t, relays n and contactors c issuch, that when the spindle w of the distant potentiometer is movedthrough an angular distance corresponding to the movement required to beperformed by the motor a, a state of unbalance is created between thetwo potentiometers. Consequently, current flows through a circuitcontaining a part of the main resistance u, contact 1), and spindle w,of the distant potentiometer, the winding q of the first relay n, andthe spindle in, contact 1), and a part of the main resistance a of theother potentiometer. Also current flows through a circuit containing apart of the subsidiary resistance :r, the adjacent contact or contactsy, 2, and one or each of the slip rings 2, 3 of the distantpotentiometer, one or each of the windings q, r of the second relay n,and one or each of the slip rings 2, 3, one or each of the contacts y,z, and a part of the subsidiary resistance :c, of the otherpotentiometer. Which of the relays is thereby brought into action by thecurrent flow depends on the extent of the unbalance created between thetwo potentiometers i. If a large angular movement is imparted to thespindle w of the distant potentiometer, a relatively heavy currentflows, and the first relay 11. comes into action causing themotor-retarding means above mentioned to be put out of action and themotor a to be rotated at a relatively high speed in the appropriatedirection. When a stat-e of balance between the potentiometers t isapproached, the current in the first relay it becomes insuii'icient tokeep this relay in action. The second relay n then causes current to besupplied to the operative contactor c through the associated resistance9, but this current is insufiicient to keep the contacts F, g of thiscontactor closed. The motor-retarding means thereupon comes into action,causing the motor a and the spindle w of the associated potentiometer tto be slowed down. When a state of balance is finally reached, thecircuits are re-opened and the system comes to rest. If, on the otherhand, a small angular movement is initially imparted to the spindle w ofthe distant potentiometer, a relatively light current flows, and thesecond relay it comes into action, causing the motor a to be rotated ata relatively low speed with the retarding means in action, and when astate of balance is reached the circuits are re-opened for bringing thesystem to rest.

In the modification illustrated by Figure 2, I dispense with theresistances 7' and contacts f 9 and arrange in the circuit of the motora a vibratory interrupter for retarding the rate of motion of the motorwhen the first relay n ceases to be eiTective, the interrupter beingoperable by an electromagnet having its winding 6 connected across themotor armature. When the first relay n is in action the interrupter 5 isshort circuited by a pair of contacts 1, 8, which are separable by anelectromagnet having its winding Si connected at opposite ends to thecontacts o of the two relays n, the arrangement being such that thiswinding is energised to separate the associated contacts only when thefirst relay ceases to function and the second relay is in action. Theinterrupter 5 then serves by intermittently breaking the motor circuitto retard the rate of motion of the motor a which, when a state ofbalance is reached between the potentiometers 75, may be brought to restby an electromagnetically operable brake having its winding it in themotor circuit. In other respects the example illustrated by Figure 2 isessentially similar to that illustrated by Figure 1.

Instead of being arranged in and adapted to break the motor circuit asillustrated in Figure 2, the vibratory interrupter may be arranged in avariety of different positions. For example it may be connected acrossthe ends of a resistance H in series with the motor a as shown in Figure3.

Alternatively the interrupter 5 may be arranged to short circuit a partof the field winding 52 of the motor a as shown in Figure l, or it maybe arranged to short circuit the armature of the motor a as shown inFigure 5.

In the example shown in Figure 6', the winding 5 of the interrupterelectromagnet has combined with it an opposing winding is which isarranged in series with the interrupter 5, and the motor a.

Where the rate of rotation of the motor a is controlled by anelectromagnetically operable friction brake, I may arrange theinterrupter 5 to short circuit the brake magnet winding 10 as shown inFigure 7.

In the example shown in Figure 8 the interrupter 5 is provided with acompound winding 6, B and is arranged in series with a shunt brakewinding Hi.

It will be understood that in all of the examples shown in Figures 3 to8, the interrupter is adapted to be short circuited as in the exampleshown in Figure 2.

By this invention I am able to efiect the desired control of a motorfrom a distant position in a very simple and convenient manner. Theinvention is not, however, restricted to the examples above described,as subordinate details may be varied to suit different requirements.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

1. An electrically actuated remote-control apparatus of the kindspecified, comprising in combination a reversible electric motor havingretarding means responsive to electric current, a pair of potentiometerseach having a main resistance and a subsidiary resistance, a pair ofelectro-magnetic contactors each adapted to control the supply ofcurrent to the motor, a pair of electro-magnetic relays adapted to bebrought into action one after the other for controlling the supply ofcurrent to the contactors, and means for putting the motor-retardingmeans into and out of action under the control of the relays. one of therelays being responsive to current controlled by the main resistances ofthe potentiometers, and the other to current controlled by thesubsidiary resistances of the potentiometers.

2. An electrically actuated remote-control apparatus as claimed in claim1, in which the contactors are provided with contacts for controllingthe supply of current to the motor-retarding means, and with windingsarranged in series with resistances, one of the relays being adapted tocontrol the supply of current directly to the contactor windings, andthe other relay being adapted to control the supply of current to thecontactor windings through the resistances.

3. An electrically actuated remote-control apparatus as claimed in claim1 and having an electro-magnetically operable vibratory interrupter forretarding the rate of rotation of the motor when one of the relays isineffective.

ALFRED REGINALD ERWIN ARNOT.

REFERENCES CITED Number 6 UNITED STATES PATENTS Name Date Tiffany Oct.12, 1915 Harle June 4, 1918 Schneider Feb. 14, 1922 Wilhjelm May 4, 1937

